1. Field of the Invention
This invention relates to a process of hydrogasification of biomass for producing high yields of methane, said process utilizing a hydrogen-rich atmosphere in a reactor capable of carrying out rapid pyrolysis.
2. Description of the Prior Art
It is known to convert biomass material to gaseous products. The main components of any such conversion are carbon monoxide, carbon dioxide, hydrogen and methane. Carbon dioxide is usually an undesirable byproduct. One known method is to use air or oxygen-enriched air for heat for the gasification reaction. It is supplied by oxidation of part of the biomass with the oxygen in the air. Unfortunately, when air or oxygen-enriched air is used, inert nitrogen is introduced into the gasifier and the product gases are thereby diluted. This dilution is undesirable for many applications. A further known method involves the use of oxygen alone. This method results in a product gas which is essentially free of nitrogen but it contains some carbon dioxide. The major disadvantage of this process is that an air separation plant is required to supply the oxygen. A further known method is to use an atmosphere of steam-oxygen. However, this method also requires an oxygen plant and high gasification temperatures. Still further, steam alone can be used to react with biomass or steam can be used along with a solid catalyst. This method requires high temperatures, thereby making it difficult to use some catalysts and also making the process more expensive to operate. Also, this process can be limited in the range of gas compositions that can be produced.